For the first 90 seconds, you crush through three different curl variations for as many quality reps as you can, each for 30 seconds. You start with a regular curl to shoulder level and then move to chin and then forehead level.

The progressive level change involves more shoulder flexion—which is one of the three main functions of your biceps muscles—so you can achieve an extended muscle burn. Just be sure not to shrug your shoulders when performing these reps.

Then you move right to the triceps for the final 90 seconds. You start with the weakest position (single-joint, isolation) and move to a stronger position (more compound, multi-joint) every 30 seconds to allow you to keep pumping out reps for some serious metabolic stress on those muscles.

To recap, here’s how it works:

Perform each move for 30 seconds, with little to no rest between moves:

Curl to shoulder

Curl to chin

Curl to forehead

Skull crusher

Face press

Chest press

Rest 1 minute. That’s 1 round. Do 3 to 5 total rounds.

For more metabolic bodybuilding routines like this and to get back in shape for the New Year, check out METASHRED EXTREME from Men’s Health!